CN-117139583-B - Process control method for reducing residual steel poured in multi-machine multi-flow continuous casting tundish

Abstract

The invention relates to a process control method for reducing residual steel poured by a multi-machine multi-stream continuous casting tundish, belonging to the technical field of continuous casting in the metallurgical industry. The method comprises the steps of (1) enabling the bottom of a tundish to be of a stepped bottom structure, enabling through holes on a retaining wall to be 8-15mm away from the bottom of an impact area, enabling a fusible baffle to be arranged inside the retaining wall, (2) reducing continuous casting pulling speed when the last furnace is poured to the middle stage, improving the outlet temperature before the last furnace is refined and outlet, and (4) closing edge flows far away from the impact area of the tundish preferentially when the current is closed, then closing the edge flows sequentially from outside to inside and finally closing central position flows, and (5) starting assembly in a time period from the middle stage of pouring of the last furnace to closing of a ladle, sizing according to casting blank requirements and stopping pouring the edge flows which are preferentially formed into a whole size by a casting blank flame cutting machine. The invention has the beneficial effects of effectively reducing residual steel poured in the tundish, improving the quality of molten steel at the end of pouring and reducing the consumption of steel materials.

Inventors

• GONG YANKUN
• GAO FUBIN
• REN CHAO
• WANG JIAN
• WEI WEI
• WEI LONG
• ZHU XIN
• FENG YANPENG

Assignees

• 邯郸钢铁集团有限责任公司
• 河钢股份有限公司邯郸分公司

Dates

Publication Date

20260505

Application Date

20230815

Claims (4)

1. 1. A process control method for reducing residual steel poured by a multi-machine multi-stream continuous casting tundish is characterized by comprising the following steps of: (1) The tundish bottom is of a stepped ladle bottom structure, the height of the impact area ladle bottom is 2-10mm higher than that of the edge flow casting area ladle bottom, and the edge flow casting area ladle bottom is 5-15mm higher than that of the central flow casting area ladle bottom; the impact area bottom is positioned in the middle of the middle ladle bottom, the central flow pouring area bottom is a left flow bottom and a right flow bottom which are close to the impact area bottom, and the rest bottoms are side flow pouring area bottoms; (2) When the last furnace of the casting times is cast to the middle stage, reducing the continuous casting drawing speed to ensure that the central flow drawing speed is the lowest drawing speed and the side flow drawing speed is +/-0.1 m/min; (3) Before the last furnace of molten steel is refined and discharged, calculating the casting time of the last furnace according to the casting time, and increasing the discharge temperature according to the casting stop extension time, wherein the temperature increasing range is calculated according to 0.5-1 ℃ per minute; (4) When the flow is closed, preferentially closing the side flow far away from the impact area of the tundish, sequentially closing the side flow from outside to inside, and finally closing the central position flow; (5) The method for assembling the casting blank includes such steps as providing the distance from the flame cutting machine to the crystallizer is N m, stopping casting the blank if N/N is an integer, and stopping casting the blank if N/N is a fraction, and stopping casting the blank if the sum of the size of the blank after passing the cutting position and the size of the blank before cutting is full.
2. 2. The process control method for reducing residual steel in a multi-machine multi-stream continuous casting tundish, as set forth in claim 1, wherein the impact zone bottom corresponds to a long nozzle of the continuous casting machine, the central stream casting zone bottom corresponds to a central position stream of the continuous casting machine, the central position stream is a left stream and a right stream which are adjacent to the impact zone bottom, and the edge stream casting zone bottom corresponds to other streams of the continuous casting machine, which are called edge streams.
3. 3. The process control method for reducing residual steel in a multi-machine multi-stream continuous casting tundish of claim 1, wherein the fusible baffle is a low carbon steel plate with a thickness of 1-3 mm.
4. 4. The method for controlling a process for reducing residual steel in a multi-machine multi-stream continuous casting tundish according to claim 3, wherein said fusible baffle is prefabricated inside a retaining wall.

Description

Process control method for reducing residual steel poured in multi-machine multi-flow continuous casting tundish Technical Field The invention relates to a process control method for reducing residual steel poured by a multi-machine multi-stream continuous casting tundish, belonging to the technical field of continuous casting in the metallurgical industry. Background The casting residue of the continuous casting tundish refers to the residual molten steel quantity in the tundish after each casting time is finished when molten steel is continuously cast, and the casting residue of the continuous casting tundish is an important index for influencing the consumption of steel materials and is also a key index for measuring the economical efficiency of a modern continuous casting machine. When the liquid level of molten steel around the immersed nozzle of the tundish is reduced below the critical height of the vortex, the vortex is generated in the position area of the immersed nozzle of the tundish, so that ladle slag and covering agent on the surface layer of the molten steel of the tundish enter a crystallizer, and casting blank slag is caused. In order to prevent slag rolling accidents of molten steel in the later pouring stage of the tundish, steel enterprises can choose the liquid level of the molten steel of the tundish to be higher than the critical height of vortex slag rolling when pouring is stopped in pouring of the tundish, so that vortex slag rolling is avoided. The higher tundish molten steel can bring larger tundish casting residue, so that the molten steel yield is at a lower level, serious waste of enterprise production cost is caused, and particularly, under the current severe market environment, how to reduce the tundish casting residue is very critical to reduce the cost and efficiency, and further reduce the consumption of steel materials. The multi-machine multi-stream continuous casting refers to that a multi-stream casting blank is produced on a continuous casting machine by using a crystallizer vibration device and a withdrawal and straightening machine which are independently arranged for each stream, and the continuous casting machines of 3 machines 3 to 8 machines 8 streams are widely applied, and most of the continuous casting machines are square and round continuous casting blanks. One or two of the multiple flows in the production are stopped due to faults, and the other residual flows can still continuously pour one ladle of molten steel. Multi-machine multi-strand continuous casting machines generally employ a long tundish provided with a plurality of water openings identical to the number of flows in order to simultaneously feed each flow of molten steel into the mold. The flow distance of molten steel in a long tundish is longer, the temperature loss and the temperature difference between the flows are larger, the temperature of molten steel at the water gap at the outermost side is lower, the molten steel is easy to block, the more the flow number is, the longer the tundish is, so that a plurality of flows are stopped simultaneously in production, the lower the blank forming amount of a casting blank is caused, and the large amount of molten steel is left in the tundish. At present, research on reducing the residual steel of a continuous casting tundish at home and abroad is mainly focused on the optimization of the tundish structure, for example, china patent application No. 201720407283.0 discloses a tundish for reducing the residual steel of the continuous casting tundish, and the method is realized by opening left and right through holes on a dam in the tundish and arranging the bottom of a stopper rod pouring area lower than the bottom of the tundish in a pouring area, and mainly aims at 1 machine 1 flow. The Chinese patent application with the application number 200710010179.9 discloses a treatment method for reducing residual molten steel in a continuous casting tundish, which mainly aims to reduce the temperature of liquid around a casting nozzle, reduce the slag discharging amount, promote the solidification of molten steel in the section of a tail blank and reduce the residual molten steel by changing the property of molten steel slag in the tundish and increasing the alkalinity and viscosity. Disclosure of Invention The invention aims to provide a process control method for reducing residual steel poured by a multi-machine multi-flow continuous casting tundish, which effectively reduces residual steel poured by the tundish, improves molten steel quality at the end of pouring, reduces iron and steel material consumption and solves the problems in the background art. The technical scheme of the invention is as follows: A process control method for reducing residual steel poured by a multi-machine multi-stream continuous casting tundish is characterized by comprising the following steps of: (1) The tundish bottom is of a stepped ladle bottom structure, the height of